President George Bush joined students at Virginia Tech university on "a day of sadness" yesterday as police identified the gunman responsible for the worst mass killing in US history as a 23-year-old Korean-born student, reports Denis Staunton in Blacksburg, Virginia.
As Mr Bush addressed a memorial convocation in the university basketball hall, thousands of students, dressed in the college colours of burgundy and orange, watched on a giant screen in a nearby football stadium.
"Those whose lives were taken did nothing to deserve their fate. They were simply in the wrong place at the wrong time," the president said.
Police identified the gunman, who killed 32 people before shooting himself, as Cho Seung-Hui, a senior student in the English department. Born in South Korea, he moved to the US at the age of eight, and had been a permanent resident alien since 1992.
He bought the two handguns used in the attack, which he held legally, within the past month, and investigators said they found notes in his dormitory room at the university that linked Cho to bomb threats made last week.
Described as a loner, Cho alarmed some members of his creative writing class with the disturbing character of the plays he wrote, according to classmate Stephanie Derry.
"His writing, the plays, were really morbid and grotesque. I remember one of them very well. It was about a son who hated his stepfather. In the play the boy threw a chainsaw around and hammers at him. But the play ended with the boy violently suffocating the father with a Rice Krispy treat," she told the campus newspaper the Collegiate Times.
Prof Carolyn Rude, chairwoman of the university's English department, said, although she did not know Cho personally, she was aware that he was regarded as a troubled student who had been referred to a college counsellor.
Carrying two handguns and multiple clips of ammunition, Cho opened fire in a dormitory building shortly after 7am on Monday and then stormed into a classroom building on the other side of the campus, chained the doors closed and started shooting students and teachers.
University president Charles Steger has defended the university's failure to close down the campus and warn students after the first shooting, which campus police initially thought was part of a domestic dispute.
"We can only make decisions based on the information you had at the time. You don't have hours to reflect on it," Dr Steger said.
As students continued to criticise the university's behaviour, Mr Bush told them it was almost impossible to make sense of events like Monday's.
"Yesterday began like any other day. Students woke up, and they grabbed their backpacks and they headed for class. And soon the day took a dark turn, with students and faculty barricading themselves in classrooms and dormitories - confused, terrified and deeply worried.
"By the end of the morning it was the worst day of violence on a college campus in American history - and for many of you here today it was the worst day of your lives."
After his address yesterday, Mr Bush and his wife, Laura, met students and relatives of the dead and injured.
Monday's massacre has rocked the rural corner of Virginia where Virginia Tech lies at the foothills of the Blue Ridge Mountains.
Shops remained closed yesterday in many nearby towns as local people, many wearing burgundy and orange ribbons, paid their respects to the dead.
Virginia governor Tim Kaine told Virginia Tech students yesterday that the world had been inspired by the response of the campus and the surrounding community.
"It's not just you that needs to maintain that spirit, but the world needs you to. The world saw you, and saw you respond in a way that builds community. The world needs that example before it."